Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 665 species
Yellow-and-black triplefin
Forsterygion flavonigrum
This is a tiny New Zealand triplefin that hangs around rocky reefs and overhangs, picking off little crustaceans. When males go into breeding colors they turn into a wild black-and-yellow flag, then they post up and guard the eggs like a grumpy little bouncer.
Yellow enteromis
Enteromius cerinus
Enteromius cerinus is a tiny Congo Basin barb that stays under 2 inches and shows a neat pattern of three dark flank spots with a darker midline. It was described in 2024, so it is basically unheard of in the aquarium trade right now, but it reads like a classic little schooling river barb if it ever shows up.
Yelloweye filefish
Pervagor alternans
This is a little reef filefish with that classic sandpapery skin and a super eye-catching yellow ring around the eye. It spends a lot of time poking around rock and coral, and when it gets spooked it kind of eases back into crevices instead of bolting. Not the most common aquarium fish, but really neat if you can get one that is eating well.
Yellowfin gambusia
Gambusia alvarezi
Tiny spring-dwellers from Chihuahua, these little livebearers zip around the surface and the males flash buttery-yellow fins when they are feeling bold. They thrive in warm, hard, alkaline water and do best as a lively species group, since they can pester slower or long-finned fish. If you like active, always-hungry top swimmers with personality, this one is a fun project fish.
Yellowfin madtom
Noturus flavipinnis
Yellowfin madtoms are tiny, secretive native catfish from the upper Tennessee River system, and they act exactly like little river goblins - hiding under flat rocks all day and cruising around at night. The cool part is the male guards the eggs under cover, and they really appreciate clean, well-oxygenated current and a rock-and-leaf-litter kind of setup.
Yellow-lined shrimpgoby
Vanderhorstia flavilineata
This is a tiny sand-dwelling shrimp goby from Papua New Guinea that likes to hover right at the front door of a burrow and bolt inside when it gets spooked. In the wild it hangs out with an alpheid (pistol) shrimp in a rubble-lined burrow, which is exactly why it does best in a tank with a sand bed and some small rubble pieces it can use as "building material." Those yellow lines and little head spots pop way more than you'd expect from a fish that barely breaks an inch.
Yellowmouth jawfish
Opistognathus nothus
This is a deepwater Atlantic jawfish that lives in burrows on sand and rubble, and it has that classic jawfish vibe of popping up like a little periscope from its hole. The yellow edging inside the mouth is the giveaway, plus the spotty head and striped/yellow-edged fins. Because it comes from about 92-100 m depth, it is not something you should treat like a typical warm, shallow-reef jawfish in a home tank.
Yellow phantom tetra
Hyphessobrycon roseus
Hyphessobrycon roseus is a small phantom-type tetra (syn. Megalamphodus roseus) from the Maroni and Oyapock river basins (French Guiana/Guianas region). It is best kept in a planted, softwater setup in a group, where males may display but are generally peaceful.
Yellow-spotted dwarf loach catfish
Zaireichthys flavomaculatus
Zaireichthys flavomaculatus is a truly tiny, bottom-hugging African loach catfish from the Congo basin that spends its time tucked into sand and gaps like a little river goblin. Its yellowish base color with blotchy/marbled spotting is the whole vibe, and it is the kind of fish you keep because you love oddball micro-predators and watching subtle behavior, not because it is always out front.
Yunnanilus longibulla
Yunnanilus longibulla
Tiny stone loach from Yunnan’s Lake Chenghai with a neat party trick - that long swim bladder helps it hover and make quick dashes along the bottom. Think cool, very hard, alkaline water and lots of sand and pebbles to nosh through. It is rarely seen in the trade, so plan for a careful, species-focused setup.
Yunnan loach
Eonemachilus altus
A petite stone loach from Yunnan, China, often listed in older books as Yunnanilus altus. It hangs around the bottom sifting for tiny bites and really perks up in a scape with smooth sand, pebbles, and steady current.
Yushan river loach
Hemimyzon yushanensis
This is a little Taiwan hillstream loach that lives its whole life clinging to rocks in fast, super-oxygenated streams. In a tank it does best in a "river" setup with smooth stones and lots of flow, where it will spend all day grazing biofilm and cruising the glass like a tiny underwater gecko.